Assistance apparatuses are known for assisting forward bending action of the upper body of a user. For example, in Japanese Patent Laid-Open No. 2009-011818, a lower back assistance apparatus is disclosed that is provided with a lumbar mounting section and a back mounting section, a joint section that connects the back mounting section to the lumbar mounting section to enable the user to tilt forward, and a first actuator to control the tilting of the back mounting section in the user forward direction in an operating state.
The lower back assistance apparatus of JP-A No. 2009-011818 is also provided with a lower limb mounting section mounted to the lower limbs of the user and a tight binding member to tightly connect the lower limb mounting section to the lumbar mounting section, restricting rotation of the lumbar mounting section in the same direction as the back mounting section. Due to the tight binding member being configured from an easily deforming material such as rubber tubing, there are occasions when looseness occurs in the tight binding member depending on the posture of the user, such that the position of the lower limb mounting section slips. When the first actuator is actuated with the tight binding member still in a loose state and the lower limb mounting section still in a slipped position. the displacement of the first actuator is sometimes spent correcting the looseness of the tight binding member and the slipped position of the lower limb mounting section, such that raising force is not appropriately transmitted to the back mounting section.